1. Field of the Invention
The present invention relates to a node and a method, which are used for transferring packets. More particularly, the present invention relates to a node and a method, which are used for transferring IP packets.
2. Description of the Related Art
At the present time, the Internet is becoming popular in the world very fast. By virtue of the Internet, people in the world are capable of communicating with each other, and the Internet also provides an environment allowing most recent information on the world. In addition, by building a network based on a technology taking advantage of the merits of the Internet within a corporation, employees of the corporation are capable of communicating with each other with a high degree of freedom. Such a network in a corporation is also useful to efforts made to share information. Moreover, operations carried out by the user to use such a network are all but the same as the operations performed to utilize the Internet. Thus, such a network offers big merits such as simple operations and a low cost to build a system. Furthermore, in order to protect the confidentiality of the corporation's internal information, the network is provided with a boundary router or a fire wall for protecting the network against an illegal access made by an outsider in an attempt to illegally obtain the information or illegally falsify the information. Such a network is known as an intranet which draws much attention nowadays. Traditionally, each corporation except a service provider designs an intranet capable of rejecting an access made by a third person having nothing to do with employees of the corporation. Also from the band point of view, the contemporary intranet has a network configuration with a high speed and, in general, is used during day times or office hours of corporations in most cases but almost not used at nights except for periodical preventive maintenance purposes. However, dedicated lines and network equipment which make accesses to an intranet operate for 24 hours a day with the power supplies thereof supplying power all the time. Thus, communication costs are wasted.